Vi sembra famigliare?! Ma i players non dovevano essere tutti uguali?!
Invece di scomodare gli hackers bastava che ascoltassero cics parecchio tempo addietro...
Ricordo vari anni fa su AR di essere stato preso in giro pesantemente anche da qualche "capoccia" su questa questione
Dal numero di aprile della PS Audio Newsletter:
"I wanted to give our readers a heads up on a new form of distortion called Software Jitter. I am not sure where the term originated, it’s what our engineering team calls it, but it’s something you’ll hear more about over time as the industry builds more computationally intense high-end music players."
"Software jitter is audible timing errors in digital audio that happen in response to a CPU or internal processor’s needs for power. As the demands on a piece of equipment’s processor increase, so too do the demands on the power supply feeding that processor, which in turn can cause slight changes in the 1 to 0 transition thresholds and thus you get jitter - which we hear as a loss of naturalness of the music and three dimensional presentation."
"This problem is well known in the computer industry: not that anyone but hackers pay any attention to it - but it is known. Computer program hackers can actually monitor the power supply of a computer’s CPU to get an idea of what is happening inside the CPU in response to various program commands when they can’t get access any other way."
"To understand how this works, imagine a car analogy for a moment. If we were to measure the electrical activity of an automobile’s engine it would increase dramatically in response to stepping on the gas pedal. The harder one presses the pedal the faster the engine runs and the greater the need for electrical energy to energize the spark plugs that control ignition in the engine. If you were depending on a clean and steady electrical system to perform a delicate task in the car, you’d find performance would vary with the demands on the car’s engine."
"In the same way, unless extremely careful attention is paid to the power supply of your digital music player, changing demands on internal processors can affect sound quality in a quite audible manner. Recognition of this problem is just one of the reasons we shifted our focus on the new Mark II PerfectWave DAC to that of multiple power supplies and silicon gates that were less sensitive to voltage fluctuations."
"The problem, however, cannot be solved entirely by proper power supply and gate technology and it will be incumbent on software designers to minimize CPU duties as well as even out the demands on the CPU so as to have as little affect as possible."
"What’s this all mean? Well, it means that even if we have bit perfect audio to start with, how that bit perfect data is served up to your music player and how it is handled within the player will have significant impact on the eventual sound quality. It will be one of the defining factors of how digital music is handled going into the future."
"Here are several quick examples for you to ponder. Differences between music server programs such as iTunes, eLyric, J River, Amarra, Pure Music etc. have as much to do with the way the software itself is written as it does with the computer that is running the program. So, the computer you choose plus the program you use will all affect the sound quality."
"I’ll go even one step further and mention the DAC hardware. In the PerfectWave DAC Mark II users have noticed what they feel is an audible and agreed upon difference between two slightly different versions of firmware running the Mark II. And what, you might ask, is the difference between the two? How the front panel display handles things - which should have zero impact on the sound, yet ....."
"There’s a whole new field opening up on the digital forefront of high-end audio and I just wanted our readers to be aware of it and have every confidence we’re on it and leading a charge to understand and tame the beast. ‘Tis interesting indeed."
"If you want to keep up with developments and the thoughts behind all this I would recommend signing up for Paul’s Daily Posts where we bring interesting notions like this to your desktop daily"